title: Incidence, etiology, and determinants associated with acute diarrhea among French forces deployed to Chad.
abstract: BACKGROUND
  This study assesses, for the first time, the incidence, etiology, and determinants associated with traveler's diarrhea (TD) among French forces deployed to N'Djamena, Chad.
  
  
  METHODS
  A prospective study was conducted based on physician consultation for diarrhea during a 5-month French forces mandate. Diarrhea was defined as ≥3 loose stools in a 24-hour period or ≥2 loose stools within the last 8 hours. For each diarrheic episode, an anonymous physician-administered questionnaire was completed and a stool sample collected. Samples were tested for parasites, bacteria, and enteric viruses. Global incidence rate was calculated using the mean number of soldiers based in N'Djamena (n = 1,024) over the 5-month period, as denominator. Incidence rates were also estimated for each of the eleven 2-week periods of stay. A case-crossover analysis estimated determinants associated with diarrhea.
  
  
  RESULTS
  A total of 240 cases of diarrhea were notified by military physicians, resulting in a global incidence rate of 49 cases per 1,000 person-months (PM). The cumulative individual risk of developing diarrhea during the study period was 0.23. The incidence per 2-week stay began at 8.8/1,000 PM, rose to 54.4/1,000 PM after 1 month, and decreased after 2 months. Of the 240 cases reported, stool samples were obtained for 196 cases. Pathogens were identified in 40% of samples; enteric viruses were predominant (28.1%). Three determinants were associated with diarrhea by multivariate analysis: diarrhea in the close circle [OR: 3.8 (2.0-7.0)]; always eating at the military mess [OR: 0.2 (0.1-0.5)]; or staying in a temporary encampment [OR: 0.3 (0.1-0.8)].
  
  
  CONCLUSIONS
  This study found a high frequency of enteric viruses and a high risk of person-to-person transmission associated with diarrhea. Eating at the military mess or staying in a temporary encampment conferred a protective effect. In addition to food-borne disease prevention, stringent hygiene measures are required to break transmission of diarrhea during military deployments.
authors.affiliation: Département d'Épidémiologie et de Santé Publique Sud, Institut de Recherche Biomédicale des Armées, Marseille, France. pommierdesantiv@imtssa.fr
authors.forename: Vincent
authors.initials: V
authors.lastname: Pommier de Santi
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Nicand
authors.forename: Gisèle
authors.initials: G
authors.lastname: Lagathu
authors.forename: Rémy
authors.initials: R
authors.lastname: Michel
authors.forename: Georg
authors.initials: G
authors.lastname: Rosenmayr
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Raingeval
authors.forename: Julien
authors.initials: J
authors.lastname: Samy
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Boutin
authors.forename: Catherine
authors.initials: C
authors.lastname: Marimoutou
mesh_terms: D000208:Acute Disease; D000328:Adult; D002596:Chad / Q000453:epidemiology; D015897:Comorbidity; D018592:Cross-Over Studies; D003967:Diarrhea / Q000453:epidemiology* / Q000382:microbiology; D004926:Escherichia coli / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000635:transmission; D005243:Feces / Q000382:microbiology*; D005602:France / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008889:Military Personnel / Q000706:statistics & numerical data*; D011446:Prospective Studies; D012307:Risk Factors; D014195:Travel; D055815:Young Adult